BARRE — Police specialists are trying to reconstruct an accident that seriously injured a girl who was riding her bicycle on Airport Road early Sunday afternoon.

According to police, 11-year-old Ally LaGue was hit by a passing pickup truck shortly before 1:30 p.m. Sunday, transported to nearby Central Vermont Medical Center by a good Samaritan and then flown by helicopter to Fletcher Allen Health Care in Burlington.

LaGue was listed in serious condition at the Burlington hospital late Monday afternoon, and police who had spoken with her parents earlier in the day said she had shown slow but steady improvement.

Though the nature of LaGue’s injuries was unclear, police said she suffered them when she was struck by a Chevrolet pickup truck while riding her bicycle near the intersection of Airport and Warner roads.

The truck, police said, was driven by Nathan Garcia, 24, of Graniteville.

Police said Garcia told them LaGue swerved in front of him while both were heading south on Airport Road.

According to police, LaGue lives nearby, and her father heard the collision and came running to her aid. Father and daughter were taken to CVMC by a passing motorist, they said.

Based on the extent of her injuries, LaGue was then flown to Fletcher Allen by the Dartmouth-Hitchcock Advanced Response Team.

While doctors were tending to LaGue in Burlington, the state police crash reconstruction team began reviewing the collision in an attempt to determine exactly how it happened.